In the processing of substrates such as semiconductor wafers and displays, a substrate is placed in a process chamber and exposed to an energized gas to deposit or etch material on the substrate. During such processing, process residues are generated and can deposit on internal surfaces in the chamber. For example, in sputter deposition processes, material sputtered from a target for deposition on a substrate also deposits on other component surfaces in the chamber, such as on deposition rings, shadow rings, wall liners, and focus rings. In subsequent process cycles, the deposited process residues can “flake off” of the chamber surfaces to fall upon and contaminate the substrate. To reduce the contamination of the substrates by process residues, the surfaces of components in the chamber can be textured. Process residues adhere to the textured surface and inhibit the process residues from falling off and contaminating the substrates in the chamber.
Typically, textured surface components are fabricated in a multiple step process. In the first fabrication step, the shape or overall structure of the component is fabricated, for example, by CNC machining of a block of metal into the desired structure. Thereafter, a second fabrication process is used to form the textured surface of the machined component. For example, the surface texturing process can include grinding, bead blasting or polishing, or combinations thereof. In one version, the textured surface is formed by directing an electromagnetic energy beam onto a surface of a component to form depressions and protrusions to which process deposits adhere well. An example of such a surface is a Lavacoat™ surface, as described for example in commonly assigned U.S. Patent Publication No. 2003-0173526 to Popiolkowski et al, published on Sep. 18, 2003, and filed on Mar. 13, 2002; and U.S. Pat. No. 6,812,471 to Popiolkowski et al, issued on Nov. 2, 2004; both of which are incorporated herein by reference in their entireties. The Lavacoat™ surface comprises depressions and protrusions to which process residues can adhere to reduce the contamination of substrates during their processing.
However, conventional processes to fabricate textured components are often expensive because of the multiple fabrication steps needed to form the component and its textured surface. The fabrication costs inhibit widespread implementation of the textured components despite the processing benefits provided by the components. The expense of conventional fabrication processes is at least in part due to the complicated multi-step fabrication procedures used in these processes, as well as the expensive fabrication equipment. For example, component fabrication machinery, such as for example, electromagnetic energy beam generating equipment, is expensive and can substantially increase the fabrication costs of the textured components.
The component fabrication time and costs are a further problem when the cleaning processes used to refurbish textured components erodes the component after several cleaning cycles. A cleaning process is typically performed once residues have accumulated on the textured component to remove the residues and refurbish the component for re-use. For example, repeated cleaning of the textured component with solutions comprising HNO3 or HF eventually erodes the textured surface of components, typically requiring the replacement of the eroded components with newly-fabricated components. Thus, the expense of fabricating the new textured surface components undesirably increases the costs associated with operating a chamber.
Accordingly, it is desirable to have a method of fabricating textured chamber components that is relatively inexpensive and efficient compared to conventional fabrication processes. It is further desirable to have a component with a textured surface to which process residues can adhere well.